1. Field of the Invention
The present invention relates to an actuator and a method for driving the same.
2. Description of the Related Art
FIG. 13 shows an actuator disclosed in Japanese Patent Laid-Open Publication No. 2009-169290.
This actuator 100 comprises a support layer 104, a first electrode layer 105, a first piezoelectric layer 106R, a second piezoelectric layer 106L, a second electrode layer 107R, and a third electrode layer 107L.
Two piezoelectric actuators 108R and 108L are formed in this actuator 100. The first piezoelectric actuator 108R is constituted with the right half 104R of the support layer 104, the right half 105R of the first electrode layer 105, the first piezoelectric layer 106R, and the second electrode layer 107R. The second piezoelectric actuator 108L is constituted with the left half 104L of the support layer 104, the left half 105L of the first electrode layer 105, the second piezoelectric layer 106L, and the third electrode layer 107L.
A torsion bar 102 is fixed to the bottom face of the support layer 104. The torsion bar 102 is interposed between the first piezoelectric actuator 108R and the second piezoelectric actuator 108L when viewed in the cross-sectional view of FIG. 13. The torsion bar 102 has a longitudinal direction perpendicular to both the lamination direction of these layers 104-107 (namely, the vertical direction in FIG. 13) and the longitudinal direction of the support layer 104 (namely, the horizontal direction in FIG. 13). A mirror 101 is provided at one end of the torsion bar 102.
A voltage of 0 volts, a negative voltage, and a positive voltage are applied to the first electrode layer 105, the second electrode layer 107R, and the third electrode layer 107L, respectively. As shown in FIG. 13, this voltage application allows the actuator 100 to be twisted so as to tilt the mirror 101.